iTunes Autoplay

Why, oh why does iTunes start playing automatically when I connect my bluetooth speakers? This seems to be an undocumented feature (aka bug). Is there any way to stop it? I was part way through a Powerpoint presentation when the speakers dropped off. I resynched and iTunes started playing a random track on top of the sound track from the presentation!!

I'm currently on a MacBook Pro running Yosemite 10.10.5, iTunes 12.3